WINDSOR, England – Queen Elizabeth II — Britain's oldest and longest-serving monarch — was celebrating her 90th birthday Thursday with a day at home with the dogs, a short walk to greet well-wishers and a family party, as the nation paid tribute to her service and stamina.
Her government and subjects held gun salutes, fireworks and speeches in Parliament in the queen's honor, and televised retrospectives offered scenes from a royal life that has stretched from the Roaring '20s to the Internet age.
"Her Majesty has been steadfast — a rock of strength for our nation, for our Commonwealth and on many occasions for the whole world," declared British Prime Minister David Cameron
He said the queen "has lived through some extraordinary times," from World War II to the moon landing, the end of the Cold War and the advent of peace in Northern Ireland.
Cameron led tributes Thursday in the House of Commons to the monarch and her "unshakable sense of duty," pointing out that the queen had provided counsel to 12 British prime ministers and met a quarter of all the U.S. presidents in history.
At dusk, the Parliament building will be lit up in the red, white and blue of the Union Jack.
Born Princess Elizabeth on April 21, 1926, she became queen at 25 upon the death of her father, King George VI, in 1952. A majority of Britons have lived under no other monarch.
The queen spent the day at Windsor Castle, leaving to greet well-wishers on a walk through the town west of London. Hundreds had lined up hours beforehand, carrying cakes, cards, balloons and Union Jack flags.
The band of the Coldstream Guards played "Happy Birthday" and royal fans snapped cellphone photos as the queen, clad in pale green, greeted local dignitaries, townspeople and tourists.
"She's such an icon and a real role model for the children of today. And I think everybody should respect her for all the years that she's given for her country," said Donna Werner, an American tourist from New Fairfield, Connecticut.
Later, the queen will light the first in a chain of 1,000 beacons to blaze across Britain and around the world, before attending a private family party at the castle.
Elsewhere, the day was being marked with an eruption of pomp. Artillery companies fired gun salutes from sites including Hyde Park and the Tower of London, and the bells of Westminster Abbey rang out in celebration.
Prince Charles, the 67-year-old heir to the throne, recorded a tribute to his mother for broadcast on the BBC World Service. He recited a passage from William Shakespeare's "Henry VIII" about the birth of the monarch's predecessor, Queen Elizabeth I:
"She shall be, to the happiness of England,
An aged princess; many days shall see her,
And yet no day without a deed to crown it."
Buckingham Palace issued three portraits by American photographer Annie Leibovitz to mark the day. One shows the queen surrounded by seven young grandchildren and great-grandchildren. The queen cradles 11-month-old Princess Charlotte in her lap, while Mia Tindall — 2-year-old daughter of the queen's granddaughter Zara Phillips and her husband Mike Tindal— stands clutching the monarch's black handbag.
Another shows the queen with Princess Anne, her only daughter. The third shows her on the steps of Windsor Castle with four of her beloved dogs: corgis Willow and Holly and dorgis (corgi-dachshund crossbreeds) Vulcan and Candy.
The queen will receive more birthday greetings on Friday, when she hosts U.S. President Barack Obama and his wife Michelle Obama for lunch at Windsor Castle.
But not everyone in Britain was succumbing to royal-mania. The anti-monarchist group Republic published a resolutely undeferential message headed "Happy Birthday Mrs. Windsor."
"A long life is no reason for a long reign," it said.